Dorsal columns are long myelinated fibers oriented along the spinal cord axis and centrally located around the lumbar spine between the dorsal roots. Researchers have found that fibers enter the dorsal horn, and are arranged in approximately v-shaped layers. Fibers that enter at a higher vertebral level form a v-shaped layer covering the layers that originated at lower levels. The nerve fiber organization is less structured below the dorsal column surface, where the fibers are two or more vertebral levels away from their point of entry. M. C. Smith et al., Topographical Anatomy of the Posterior Columns of the Spinal Cord in Man, 107 Brain 671 (1984). FIG. 1 is a cross sectional view of different vertebra through the spinal cord with symbols illustrating the spinal nerve pathways through the dorsal column.
Chronic pain originating in the lower back is quite common. Spinal cord stimulation is an accepted therapy for chronic pain. However, physicians have found that it can be difficult to properly position the spinal cord stimulation lead to achieve good pain relief for lower back pain. As illustrated in FIG. 1, nerve fibers associated with lower back pain (S4 to L5), are only close to the dorsal column surface for a short distance and are consequently difficult to locate. Physicians who consider properly treating lower back pain with SCS must develop an effective SCS technique and must learn to manipulate a stimulating lead with unusual skill and patience. Such a technique often involves implanting a stimulating device and carefully positioning at least one stimulating lead into a patient's spinal area. Even if the technique is performed properly, the leads may need to be repositioned over time. Repositioning the stimulating leads is typically an invasive surgical procedure that carries risks and requires great patience, care, and skill.
Accordingly, it is desirable to provide a system and method that physicians can readily adopt for stimulating the spinal cord, particularly areas of the spinal cord that have low surface concentrations of readily manipulated nerves such as those in the dorsal columns. In addition, it is desirable to provide a system and method for non-invasively relocating an electrical field after the system is implanted. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.